Flow augmenting device for oil wells



G; W. STOUT Dec. 29, 1970 FLOW AUGMENTING DEVICE FOR 0111 WELLS Due/va or Geo/ 9e 511650412 FQ' 3 Z Filed Nov. 22, 1968 United States Patent 0 US. Cl. 417l72 2 Claims ABSTRACT OF THE DISCLOSURE A flow augmenting steam operated gas lift at the lower end of a string of production tubing in a cased well, the

lift having a venturi, a nozzle to direct a steam jet upwardly through the venturi, means conducting steam to the nozzle, heater means ahead of the nozzle through which the steam is diverted to heat production fluid flow and in advance of the venturi and flow directing means to accelerate the rate of flow of production fluid and to direct it into the venturi.

This invention has to do with a flow augmenting device for oil wells and is more particularly concerned with an improved gas lift type of device adapted to be engaged in the production tubing in a cased oil well and to estab lish, assist and/or maintain the flow of production fluid therethrough.

For many years it has been common practice to provide gas lifts in free flowing oil wells to increase the flow rate of the production and to provide such devices in nonfree flowing wells to induce and maintain flow of production.

Such devices are extremely simple and include a sublike body, engageable in a string of production tubing, having a venturi therein in axial alignment with and communicating with the adjacent portions of the production tubing, an axially upwardly disposed, central, nozzle within the venturi and means for conducting high pressure gas through the nozzle for discharge therefrom, upwardly through the venturi. The high pressure jet of gas issuing from the nozzle creates a minus pressure in the lower portion of the venturi lifting the production fluid occurring below the device, upwardly therethrough. As the production fluid is lifted it is eventually engaged by the jet of gas to be accelerated greatly thereby and scrubbed and lightened (aerated) thereby, thereby effectively causing it to flow upwardly through the tubing.

A typical means for conducting high pressure gas to such devices includes means for sealing the annulus between the production tubing and the casing of the well, below the device and at the top of the well structure, means at the top of the well structure to introduce high pressure gas into said annulus and means within the device to conduct said gas from the annulus to the nozzle.

Ordinarily the gas employed in operation of such devices includes air or in some instances natural or pe- 60 troleum gases. The latter has the advantage of blending with the production fluid to more effectively lighten and thin said fluid and at the same time conserves of natural gas that might otherwise be disposed of as waste.

Many wells produce oil which is extremely thick or 6 way up through the production tubing and so as to pre- 70 vent it from becoming thick and non-free flowing in the tubing.

Patented Dec. 29, 1970 ice It is an object of my invention to provide a flow augmenter or gas lift wherein the gaseous medium employed is steam and is such that it serves to heat the production fluid and make it more fluid.

Gas lifts provided by the prior art affect and act upon the production fluid at their lower ends, below their nozzles, by virtue of the minus pressures generated and are such that even if operated by steam would not affect heating of the production fluid in advance of the nozzle and venturi means and in such a manner as would heat the production fluid, to thin it and thereby enhance the operation of the devices.

Further, such gas lifts provide no means below the venturi and nozzle to induce or enhance the operation and function of the devices and in fact include structure which tend to impede the flow of production fluid therethrough and interfere with the function of the venturi and nozzle, or jet.

An object of my invention is to provide a venturi type gas lift device adapted to be operated by high pressure steam or superheated steam, having means for heating the production fluid in its lower end and below the venturi and having means for accelerating the flow rate of the heated production fluid in advance of and as it moves upwardly through the device and into the venturi to supplement and enhance the operation of the venturi.

The foregoing and other objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and embodiment of my invention throughout which description reference is made to the accompanying drawing, in which:

FIG. 1 is a vertical elevational view of my invention showing it engaged in a well structure;

FIG. 2 is an enlarged detailed sectional view taken substantially as indicated by line 2-2 on FIG. 1;

FIG. 3 is a sectional view taken substantially as indicated by line 33 on FIG. 2;

FIG. 4 is a transverse sectional view taken substantially as indicated by line 44 on FIG. 2; and

FIG. 5 is a transverse sectional view taken substantially as indicated by line 55 on FIG. 2.

In FIG. 1 of the drawings I have shown a well =bore W with a casing 10 therein. The casing 10 is shown provided at its lower end with a shoe 11 and is closed at its upper end with a suitable head 12. The exact form and nature of the head 12 can be varied widely without departing from the spirit of this invention.

Arranged within the casing 10 is an elongate string of production tubing T. The tubing T and casing 10 cooperate to define an annulus A coextensive with the longitudinal extent of the tubing string within the casing.

The tubing T extends upwardly through the head 12, in sealed relationship therewith and is adapted to connect with a suitable means for receiving production fluid flowing upwardly through the tubing.

The head 12 is provided with a lateral pipe fitting 13 communicating with the annulus A, at the upper end thereof. A steam line 14 extending from a suitable steam generating means (not shown) is connected with the pipe fitting 13.

The device D that I provide is an elongate assembly and includes a venturi portion V at its upper end, which portion is shown connected with the lower end of the tubing T. The device D further includes packing means at its lower end portion which means can connect with a lower section or portion of the production tubing T or can, as illustrated, connect with a suitable perforated liner L. The device D further includes nozzle means within the venturi portion or section, steam transfer means S to conduct steam from the annulus A to the nozzle means N, heater means H to heat the production fluid in the lower end of the construction and/or liner L and flow accelerating means F related to the venturi means and below and/or about the nozzle means N.

The venturi portion V of my construction is made up of an upper elongate fluid conducting section having a male pin 16 at its upper end to facilitate connecting that section with the lower end of the tubing T and having a central upwardly divergent flow passage 17. The venturi portion further includes an elongate cylindrical lower section 18 with a plurality (4) of downwardly opening circumferentially spaced, upwardly convergent, upwardly and radially inwardly inclined flow passages 19 which passages converge with and fare into a central upwardly opening upwardly convergent flow passage 20 in the upper end of the section 18.

The upper and lower sections are arranged in axial alignment and in end to end engagement with each other and with the passages 17 and 20 in register and communication with each other. The lower end of the passage 17 and upper end of passage 20 are equal in diametric extent and are preferably rounded and/ or dressed where they join to fare smoothly one into the other.

It will be apparent that the passages 17 and 20 cooperate to define a typical or conventional venturi and that the upwardly convergent passages 19 not only direct and conduct fluid to the lower inlet end of the venturi but also serve to accelerate the rate of flow of the fluid flowing upwardly therethrough and in such a manner that the fluid entering the venturi is flowing at an accelerated rate. Further, the passages serve to smooth out and control the flow of fluid entering the venturi and eliminate undesirable turbulence that might otherwise adversely alfect the efliciency of the venturi.

In addition to the above, the section 18 is provided with a central longitudinal bore 21 which opens upwardly in the lower end of the passage 20 and between the upper ends of the passages 19 and which communicates with a threaded socket 22 entering the bottom of the section 18 at the center thereof.

The structure that I provide next includes an elongate vertically extending body with a central longitudinal bore 31. The upper end of the body 30 is provided with an enlarged central upwardly opening socket 32 in which the section 18 is slideably engaged and seated and in which the lower end of the section 15 is threadedly engaged, as at 33. It will be apparent that the section 18 is held captive in the body and in proper relationship therewith and with the section 15 by the inter-engaged relationship of the section 15 and the body 30.

The lower open ends of the passages 19 communicate with the bore 31.

Arranged centrally in the bore 31 of the body 30 is an elongate cylindrical carrier 34 with a central longitudinal bore 35. The carrier has a flat upper end in a common plane with the bottom of the socket 32 and an internally threaded lower end. The carrier 34 is supported and carried by a bridge structure including a pair of diametrically opposite, radially outwardly extending spoke-like tubular conductors 36 with longitudinal, radially extending gas or steam conducting ports 37 extending therethrough and which establish communication betwen the bore and the exterior of the body.

The bridging structure or conductors 36 supporting the carrier in the body are of minimum lateral or horizontal cross-sectional extent and are greater in vertical cross-sectional extent than the lateral or horizontal extent and are suitably hydraulically streamlined to afford minimum resistance and to establish minimum turbulence in and to the production fluid flowing upwardly through the body and in the annulus defined by the carrier 34 and the bore 31.

The bore 35 is equal in diameter with the major diametric extent of the threaded socket 22 and the upper end of the carrier establishes flat bearing engagement on the bottom of the section 18, with the bore 35 and socket 22 in alignment with each other. Fixed to and depending from the lower end of the carrier 34 is an elongate tubular heater probe 40, the lower end of which is closed by a downwardly and inwardly convergent hydraulically streamlined lower end portion 41. The upper end of the probe 40 is threadedly engaged in the lower end of the carrier, as clearly illustrated in the drawings. The probe 41 can be of any desired length and is preferably sufficiently long to extend to the lower terminal end of the body or to the lower terminal end of a related packer, indicated by a reference character P.

In practice, the probe can be made sufficiently long to extend downardly and well into the liner L.

The lower terminal end of the body 30 is provided with a male pin 38 to facilitate connecting the body with the packer P.

The packer P can be of any suitable form and construction and is shown as including an elongate vertically ex tending fluid conducting body 45 with a pair of upwardly disposed rubber packing cups 46 and a pair of downwardly disposed rubber packing cups 47. The upper end of the packer body connects with the pin 38 at the lower end thereof and the lower end of the packer body connects with the upper end of the liner L.

The cups of the packer engage the casing 10 of the well to seal the lower end of the annulus A.

The nozzle means N that I provide includes an elongate tubular nozzle 50 with an elongate cylindrical upper portion 51 slidably engaged in the bore 21 of the lower section 18 of the venturi portion of the construction. The upper portion 51 has an upwardly and inwardly convergent tip 52, defining an orifice and projecting upwardly from the bore 21 and into the throat portion of the venturi defined by the passage 21. The nozzle further includes an elongate cylindrical lower portion slidably engaged in the bore 35 of the carrier. The upper portion of said lower portion is threadedly engaged in the socket 23 in the section 18. Accordingly, the nozzle is carried by the section 18 and depends therefrom to slidably engage in the bore 35 of the carrier.

The threaded connection between the nozzle and section 18 is such that the nozzle can be adjusted longitudinally of the construction for the purpose of orienting the tip 52 in proper longitudinal position in the venturi.

The lower end of the nozzle terminates above the ports 37 and the lower portion thereof carries a suitable seal 55 to seal between the nozzle and the bore 35.

In practice, if desired and as illustrated, I provide an elongate tubular steam conducting stinger threadedly engaged in the lower end of the tubular nozzle to communicate therewith and depending freely therefrom and into the lower portion of the heater probe 40.

With the stinger 60, steam flowing through the ports 37 into the bore in the carrier flows downwardly through the probe to heat the probe and thence upwardly through the stinger and into the nozzle.

If the stinger 60 is not provided the steam entering the bore of the carrier flows directly into the nozzle and a portion thereof is free to flow and circulate downwardly in the probe. In such a case, the probe is heated, but not so effectively as when the stinger is provided. Provision of the stinger 60 depends greatly on the longitudinal extent of the probe. The greater or longer the probe is, the more desirable it is to provide a stinger.

Finally, in the preferred carrying out of my invention and as illustrated in the drawings, the exterior of the body is provided with an annular outwardly opening channel about its outer circumference which channel is of considerable longitudinal or axial extent and into which the outer ends of the ports 37 open. The channel 70 is surrounded and closed by a perforated sleeve 71 suitably fixed to the body 30. The channel 70 and sleeve 71 serve to screen and protect the outer open ends of the ports and prevent said ports from becoming plugged with foreign matter and also serve to assure the free flow of gas or steam, from the annulus A, into the ports and thence through the remainder of the construction.

In operation and with the structure assembled and arranged in a well, as illustrated, steam introduced into the top of the annulus A flows downwardly therethrough, heating the production tubing T and maintaining the production fluid therein heated and highly fluid. The steam then flows through the ports 37 into the bore 35 and is caused to flow down through the probe 40 to heat the probe. The heated probe heats the production fluid in the construction below the venturi and makes it more fluid. The steam then flows upwardly through the stinger and the nozzle and is discharged upwardly from the tip 52 of the nozzle as a high velocity jet, into and through the throat of the venturi. The steam jet flowing through the venturi creates a minus pressure in the lower portion of the venturi, impinges with production fluid in the venturi to accelerate it and urge it upwardly through the construction and into the tubing T and also heats the oil thus acted upon.

The minus pressure created in the venturi lifts or draws the production fluid upwardly from within the liner, past or by the probe, to be heated and made more fluid thereby and thence upwardly through the upwardly convergent passages 19 to be accelerated thereby and so that as the production fluid enters the venturi its rate of flow has already been accelerated to an appreciable degree and in such a manner as to materially enhance the efliciency and effectiveness of the venturi.

Having described only a typical preferred form and carrying out of my invention, I do not wish to be limited to the specific details herein set forth but wish to reserve to myself any variations and modifications that may appear to those skilled in the art.

Having described my invention, I claim:

1. In combination, a cased well, a production tubing extending longitudinally through the Well and cooperating with the casing thereof to define an annulus, means for introducing high pressure gas into the upper end of the annulus, a device arranged in the tubing to define an elongate axially extending venturi with a restricted throat portion and in axial alignment with and communicating with said tubing, a tubular nozzle arranged centrally in the device and having an upwardly disposed orifice tip positioned centrally in the throat portion of the venturi, means communicating with and between the nozzle and the annulus to conduct gas from the annulus to said nozzle, a plurality of downwardly opening circumferentially spaced longitudinally upwardly and inwardly inclined upwardly convergent passages in the device about the nozzle and converging with and faring into the lower portion of the venturi, a bore in said device below the passages communicating with a source of production fluid and with which said passages communicate, said'high pressure gas is heated and said device includes an elongate tubular heater probe communicating with said means communicating with the annulus and the nozzle and arranged centrally in said bore and extending downwardly therethrough to heat production fluid in said bore.

2. The combination set forth in claim 1 wherein said nozzle has an elongate tubular stinger depending freely in-to and through said probe to terminate at the lower end portion thereof whereby the gas flowing through the device is caused to flow downwardly through said probe and then upwardly through said stinger and into the nozzle.

References Cited UNITED STATES PATENTS 642,046 1/1900 Miller 103-264 960,023 5/1910 Knight 103-232 973,351 10/1910 Hoffman 103-260 988,223 3/1911 Sweeny et a1 103-264 1,052,002 2/ 1913 Kent 103-264X 2,182,545 12/1939 Pace 103-260X 2,675,081 4/1954 Nowak 103-260X 3,216,368 11/1965 Waldron 103-260 3,234,890 2/1966 Adams et a1 103-260 ROBERT M. WALKER, Primary Examiner W. J. KRAUSS, Assistant Examiner U.S. C1. X.R. 

